Concurrent Strength and Endurance Training: From Molecules to Man
AMPK↔mTOR interference mechanism
Key Findings
Strength training raises muscle mass and strength; endurance training raises maximal oxygen uptake and metabolic capacity — adaptations with little overlap
When strength and endurance are trained simultaneously, a potential interference in strength development takes place "in specific situations" — first described by Hickson in 1980; work since has given evidence for and against it
Molecular explanation: different exercise forms induce antagonistic intracellular signalling; activation of AMPK by endurance exercise may inhibit mTOR and its downstream targets, i.e. signalling to the protein-synthesis machinery
Full text; not checked against the abstract: mTOR/p70S6K as the resistance-exercise anabolic pathway and PGC-1α-mediated mitochondrial biogenesis downstream of AMPK
The interference is on strength development; the abstract does not claim that endurance adaptation is impaired by strength work
Practical Application
A 2006 mechanistic review: concurrent strength and endurance training interferes with strength development in specific situations (evidence for and against since Hickson 1980), and the candidate mechanism is AMPK activation by endurance exercise inhibiting mTOR signalling to protein synthesis. It explains why the two stimuli can conflict; it does not prescribe how far apart to place them.
Inference, not tested here: for a masters/hybrid athlete whose goal is hypertrophy/strength, do not place heavy endurance immediately before the strength stimulus — the AMPK signal is the reason
Limitations
2006 review; the signaling picture has since grown more complex (mTORC1 vs mTORC2, autophagy, role of training status)
Mechanism ≠ direct prescription — acute signaling does not always predict chronic adaptation
Narrative review, no systematic method or pooled effect sizes
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B+: narrative review without systematic method; mechanism paper with no pooled data
Content correction 2026-09-27
Level B+ -> C+ per KB-LEVEL-RUBRIC (narrative mechanistic review, no systematic method).
"Separate sessions ideally ≥6-24 h" and the glycogen/train-low bullet -> not in the abstract; removed, spacing now points to SYNTH-01/REF-588. Lead bullet is the review's own claim (interference in specific situations, AMPK→mTOR candidate mechanism).
p70S6K/PGC-1α details labelled as full-text content.
2026-10-01: cross-reference repointed from a merged framework to the one that replaced it (SYNTH-01→31, 05→34, 09→70, 12/15→32, 19→26).
2026-10-01: citation of the superseded pointer SYNTH-01 repointed to SYNTH-31, which carries the cited content.